Digital evaluation method of fracturing fluid damage in tight oil reservoirs——by taking P59 well as an example

In the process of fracturing, the residue of fracturing fluid is easy to damage the reservoir, especially the tight reservoir, which affects the development effect. In order to determine the damage of fracturing fluid to tight reservoir, the damage evaluation method of core displacement used in the past has many problems, such as large number of cores, high displacement pressure, long experimental period and high cost. Therefore, the conventional fracture fluid damage evaluation method cannot meet the needs of rapid fracture fluid damage evaluation of this kind of reservoir. Based on the technology of digital core modeling and CT scanning, combined with the simulation of fracturing fluid damage and seepage in tight reservoir, a digital evaluation method of fracturing fluid damage in tight reservoir is formed. The experimental results show that the porosity and permeability of the tight reservoir were obviously reduced after fracturing fluid immersion. On the third day, the porosity and permeability loss rate reached 70%. Compared with the results of the core flooding experiments, the coincidence rate was above 90%, which provides a new way for damage evaluation of fracturing fluid in tight reservoir.